They can get to at least 30 feet tall in a frost free climate. They don't do well in indoor conditions. They are usually sold as indoor palms because they are really cheap to grow. They make pretty decent potted palms outdoors during the summer depending on how they are grown before reaching the store though in part sun.
-Alex

You don't have to bring it in until nights get below 32F. the more it's outdoors the better for it, though protect it from high winds and blazing, hot sun. Water it a LOT while it's living outdoors, as long as the soil is well drianing. Not to worry about 30' trunk... very unlikely it will get more than a foot of trunk as a potted indoor plant... though possible if you keep it outdoors most of its life.